The Measurement of Engine Thrust in an Altitude Test Facility

2015 ◽  
Author(s):  
Keyword(s):  
Test Facility ◽  
Engine Thrust

From Measurement Uncertainty to Measurement Communications, Credibility, and Cost Control in Propulsion Ground Test Facilities

1985 ◽  
Vol 107 (2) ◽  
pp. 165-172 ◽  
Author(s):  
R. E. Smith ◽  
S. Wehofer
Keyword(s):  
Measurement Uncertainty ◽  
Cost Control ◽  
Performance Testing ◽  
Evaluation Process ◽  
Test Facility ◽  
Engine Test ◽  
Measurement Evaluation ◽  
Engine Thrust ◽  
Improve Measurement ◽  
Ground Test

In the past several years significant advances have been made in altitude ground test facilities with respect to measurement accuracy and measurement cost control. To a large measure, the advances have been the result of the application of comprehensive measurement uncertainty evaluation programs. This paper discusses the specific measurement evaluation process used in the Engine Test Facility, Arnold Engineering Development Center. To explain this process, the reader is guided through the measurement process for engine thrust, an extremely critical parameter for propulsion performance testing. Although this paper focuses on the measurement of engine thrust, the overall objective is the general measurement evaluation process and its uses. The approach presented can be applied to any type measurement system. First, an overview of the measurement uncertainty methodology and its application in altitude engine test cells is presented. The paper concludes with a discussion of how measurement uncertainty results can be utilized to improve measurement understanding and presents the means to identify factors that must be controlled to achieve a reliable and accurate measurement assessment.

scholarly journals Drag Management in High Bypass Turbofan Nozzles for Quiet Approach Applications

2011 ◽  
Author(s):  
P. Shah ◽  
A. Robinson ◽  
A. Price ◽  
Z. Spakovszky
Keyword(s):  
Noise Level ◽  
Jet Noise ◽  
Swirl Flow ◽  
Test Facility ◽  
Engine Thrust ◽  
Configuration Change ◽  
Swirl Angle ◽  
Maximum Benefit ◽  
Air Brakes ◽  
Flow Drag

The feasibility of a drag management device that reduces engine thrust on approach by generating a swirling outflow from the fan (bypass) nozzle is assessed. Deployment of such “engine air-brakes” (EABs) can assist in achieving slower and/or steeper and/or aero-acoustically cleaner approach profiles. The current study extends previous work from a ram air-driven nacelle (a so-called “swirl tube”) to a “pumped” or “fan-driven” configuration, and also includes an assessment of a pylon modification to assist a row of vanes in generating a swirling outflow in a more realistic engine environment. Computational fluid dynamics (CFD) simulations and aero-acoustic measurements in an anechoic nozzle test facility are performed to assess the swirl-flow-drag-noise relationship for EAB designs integrated into two NASA high-bypass ratio (HBPR), dual-stream nozzles. Aerodynamic designs have been generated at two levels of complexity: (1) a periodically spaced row of swirl vanes in the fan flowpath (the “simple” case), and (2) an asymmetric row of swirl vanes in conjunction with a deflected trailing edge pylon in a more realistic engine geometry (the “installed” case). CFD predictions and experimental measurements reveal that swirl angle, drag, and jet noise increase monotonically, but approach noise simulations suggest that an optimal EAB deployment may be found by carefully trading any jet noise penalty with a trajectory or aerodynamic configuration change to reduce perceived noise on the ground. Constant speed, steep approach flyover noise predictions for a single-aisle, twin-engine tube-and-wing aircraft suggest a maximum reduction of 3 dB of peak tone-corrected perceived noise level (PNLT) and up to 1.8 dB effective perceived noise level (EPNL). Approximately 1 dB less maximum benefit on each metric is predicted for a next-generation hybrid wing/body aircraft in a similar scenario.

scholarly journals Drag Management in High Bypass Turbofan Nozzles for Quiet Approach Applications

2013 ◽  
Vol 136 (2) ◽  
Author(s):  
P. Shah ◽  
A. Robinson ◽  
A. Price ◽  
Z. Spakovszky
Keyword(s):  
Noise Level ◽  
Jet Noise ◽  
Swirl Flow ◽  
Test Facility ◽  
Engine Thrust ◽  
Configuration Change ◽  
Swirl Angle ◽  
Maximum Benefit ◽  
Air Brakes ◽  
Flow Drag

The feasibility of a drag management device that reduces engine thrust on approach by generating a swirling outflow from the fan (bypass) nozzle is assessed. Deployment of such “engine air-brakes” (EABs) can assist in achieving slower and/or steeper and/or aeroacoustically cleaner approach profiles. The current study extends previous work from a ram air-driven nacelle (a so-called “swirl tube”) to a “pumped” or “fan-driven” configuration and also includes an assessment of a pylon modification to assist a row of vanes in generating a swirling outflow in a more realistic engine environment. Computational fluid dynamics (CFD) simulations and aeroacoustic measurements in an anechoic nozzle test facility are performed to assess the swirl-flow-drag-noise relationship for EAB designs integrated into two NASA high-bypass ratio (HBPR), dual-stream nozzles. Aerodynamic designs have been generated at two levels of complexity: (1) a periodically spaced row of swirl vanes in the fan flowpath (the “simple” case), and (2) an asymmetric row of swirl vanes in conjunction with a deflected trailing edge pylon in a more realistic engine geometry (the “installed” case). CFD predictions and experimental measurements reveal that swirl angle, drag, and jet noise increase monotonically but approach noise simulations suggest that an optimal EAB deployment may be found by carefully trading any jet noise penalty with a trajectory or aerodynamic configuration change to reduce perceived noise on the ground. Constant speed, steep approach flyover noise predictions for a single-aisle, twin-engine tube-and-wing aircraft suggest a maximum reduction of 3 dB of peak tone-corrected perceived noise level (PNLT) and up to 1.8 dB effective perceived noise level (EPNL). Approximately 1 dB less maximum benefit on each metric is predicted for a next-generation hybrid wing/body aircraft in a similar scenario.

Design and Development of a Convective Air-Cooled Turbine and Test Facility

1961 ◽  
Vol 83 (1) ◽  
pp. 9-17
Author(s):  
W. F. Weatherwax
Keyword(s):  
Axial Flow ◽  
Weight Ratio ◽  
Fold Increase ◽  
Test Facility ◽  
Inlet Temperature ◽  
Air Cooling ◽  
Turbine Inlet Temperature ◽  
Jet Engine ◽  
Engine Thrust ◽  
Turbine Inlet

Demands for higher jet engine thrust-to-weight ratios to satisfy the needs for high Mach number and vertical take-off aircraft are continually increasing. Since World War II, the three-fold increase in thrust-to-weight ratio can be attributed almost entirely to the development of lightweight construction and the axial-flow compressor, and little credit can be given to the meager 200-F increase in turbine-inlet temperature. Increasing turbine-inlet temperature, beyond present-day material limits of 1600-1700 F, by convective air cooling, will increase the jet-engine thrust-to-weight ratio and will markedly improve the performance of the turboprop and bypass engines. The partial results of a program undertaken by the author’s company to develop a fully cooled, flight-type, turbine and test facility are reported. The design heat-transfer considerations are discussed, the test facility described, and performance results to date are given.

Radiation Damage Studies with the HVEM

1972 ◽  
Vol 30 ◽  
pp. 680-681
Author(s):  
J. J. Laidler ◽  
B. Mastel
Keyword(s):  
Radiation Damage ◽  
Stainless Steels ◽  
Volume Expansion ◽  
Austenitic Stainless Steels ◽  
Test Facility ◽  
Fast Breeder Reactors ◽  
Breeder Reactors ◽  
Under Construction ◽  
Development Laboratory ◽  
Insight Into

One of the major materials problems encountered in the development of fast breeder reactors for commercial power generation is the phenomenon of swelling in core structural components and fuel cladding. This volume expansion, which is due to the retention of lattice vacancies by agglomeration into large polyhedral clusters (voids), may amount to ten percent or greater at goal fluences in some austenitic stainless steels. From a design standpoint, this is an undesirable situation, and it is necessary to obtain experimental confirmation that such excessive volume expansion will not occur in materials selected for core applications in the Fast Flux Test Facility, the prototypic LMFBR now under construction at the Hanford Engineering Development Laboratory (HEDL). The HEDL JEM-1000 1 MeV electron microscope is being used to provide an insight into trends of radiation damage accumulation in stainless steels, since it is possible to produce atom displacements at an accelerated rate with 1 MeV electrons, while the specimen is under continuous observation.

Assessing the Impact of the Inlet Total Pressure Distortion on the Turbofan Thrust

2018 ◽  
pp. 19-30
Author(s):  
Yu. A. Ezrokhi ◽  
E. A. Khoreva
Keyword(s):  
Total Pressure ◽  
External Compression ◽  
Average Value ◽  
Inlet Distortion ◽  
Air Inlet ◽  
Engine Thrust ◽  
Relative Value ◽  
Main Effect ◽  
Pressure Recovery Factor ◽  
The Impact

The paper considers techniques to develop a mathematical model using a method of «parallel compressors». The model is intended to estimate the impact of the air inlet distortion on the primary parameters of the aero-engine.  The paper presents rated estimation results in the context of twin spool turbofan design for two typical cruiser modes of flight of the supersonic passenger jet. In estimation the base values σbase and the average values of the inlet ram recovery σave remained invariable. Thus, parametrical calculations were performed for each chosen relative value of the area of low-pressure region.The paper shows that an impact degree of the inlet distortion on the engine thrust for two modes under consideration is essentially different. In other words, if in the subsonic mode the impact assessment can be confined only to taking into account the influence of decreasing average values of the inlet total pressure, the use of such an assumption in the supersonic cruiser mode may result in considerable errors.With invariable values of the pressure recovery factor at the engine intake, which correspond to the speed of flight for a typical air inlet of external compression σbase, and average value σave, a parameter Δσuneven  has the main effect on the engine thrust, and degree of this effect essentially depends on a difference between σave and σbase values.

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